Title:
SAND COVER MECHANISM OF SEABED BORING DEVICE
Document Type and Number:
Japanese Patent JP3020741
Kind Code:
B2
Abstract:
PURPOSE: To prevent sand from flowing into a bored hole, enhance the ability of a device to bore holes and reduce costs by providing at the lower end of a guide pipe a slide cover for covering the mouth of a bored hole when lowered, the guide pipe guiding a drilling rod down to the seabed.
CONSTITUTION: To perform the construction work of crushing the rock 3R of the seabed 3, a ship 2 on the sea is towed to a work site and a support 21 is put down to the seabed 3 to position the ship 2, and a mast 4 is suspended to extend the rod 7 of a rock drilling machine 6 and boring is started by a bit 9. While the bit 9 is pressed against the rock 33R by application of thrust to the rod 7, boring is performed simultaneous with striking and rotation of the bit and sludge then formed is discharged upwards through a guide pipe 10, together with a flushing fluid F. As sand 13 or the like located near the mouth of the hole bored is discharged, a slide cover 11 seated thereon is gradually lowered and is seated on the rock 3R and prevents sand 13 from flowing in from all directions due to a tide T. The ability of the device to bore holes is thus enhanced while the time required for the work can be shortened.
Inventors:
Kazuyuki Ohta
Application Number:
JP20153392A
Publication Date:
March 15, 2000
Filing Date:
July 28, 1992
Export Citation:
Assignee:
Furukawa Metal Co., Ltd.
International Classes:
E21B7/12; E21B15/02; E21B21/00; (IPC1-7): E21B21/00; E21B7/12; E21B15/02
Domestic Patent References:
| JP4169694A | ||||
| JP5474203A | ||||
| JP5935492U |
Attorney, Agent or Firm:
Tetsuya Mori (2 others)